1. Field of Invention
The present invention relates to a power tool having a tool bit that performs a predetermined operation by linearly moving in its axial direction.
2. Description of the Related Art
German Patent Publication No. 19716976 discloses a hammer drill including a crank mechanism and a clutch mechanism within a motion converting mechanism housing chamber. The clutch mechanism is switched between a power transmission state to activate the crank mechanism and a power transmission interrupted state not to activate the crank mechanism by manually operating a clutch switching member. The clutch switching member is disposed on the upper surface of the power tool body in order to enhance an operability of the power tool.
As to the motion converting mechanism housing chamber, lubrication is necessarily required for the crank mechanism and the clutch mechanism. In this connection, the total volume of the motion converting mechanism housing chamber should preferably be minimized in order to enhance the efficiency of the lubrication. Thus, it is necessary to take both the disposition of the clutch switching member and the structure of the motion converting mechanism housing chamber into account when designing the inner structure of the power tool.